SIP Trunk (ITSP) and MoH issue

Hello everyone--i've got a client with a SIP trunk, running through CUBE. After a painful process of getting the AA to work properly after the migration, they are having MoH issues now. What's happening is internal users hear ringback, MoH, etc. fine; external users on the SIP trunk hear dead silence. Any suggestions?

That does help, and yes it is callmanager. It's actually Business Edition, if that makes a difference. The MoH streams do not appear to be enabled for multicast, either, at least from what I can tell they don’t. I'm still trying to learn as I go...

Typically this error message is indicating "no resources available" tomake the call. This could be due to a number of reasons, such as MTP,media resources, region settings, etc... Check your MRG config, I believe itis because a transcoder is failing to be allocated. Internal callers what aretheir regions set for? I assume they are using G.711 within region. Try and changethe voice class codec on the gateway to codec preference 1 g711ulaw and test.If calls work you know that is where your problem is.